It's 9:37 p.m., and I'm finally squeezing in some bike repair time. Tonight, I should be done. Actually, I am done, but I can't stop. From a mechanical standpoint, my last project is pointless, but it shows what kind of home mechanic I have become: I'm coating the crimped end caps on my bike's shifter cables with liquid electrical tape. It might hold the end caps on longer, I rationalize, or maybe keep the cables from fraying - okay, it's dumb - the end caps are plenty. But this rubbery substance, which I discovered while repairing my doorbell wiring, is bright red. It looks cool, I think, as I smooth a drip. I'm glad my wife doesn't know this is why I'm down here.

I started this journey to tear apart my dirt-splattered, ghost-shifting, front-end-clunking Kona Stinky 5, clean and inspect every part, and rebuild it as a novel way to pass the long, cold nights of a Maine winter. It seemed perfect: It involved bikes, but not riding the trainer after the kids went to bed. Plus, I'm a capable home mechanic, though I hadn't done any of my own maintenance for the last few years - not enough time. But I'd work slowly, a little bit every few nights. I'd use my hands, savor the feeling of self-sufficiency, get in tune with my bike's idiosyncrasies, and maybe learn something new.

"Maybe you should paint the living room," my wife, Jen, lovingly suggested. "I hate this wallpaper."

But I was ready for her. "Let me do this," I said, "and I'll be able to fix the shifting on your mountain bike." It worked. All that beige would wait. So I descended into the basement, kicked aside some summer toys from a corner and set up The Shop: my toolbox, a folding table, workstand, manuals (Bicycling's Complete Guide to Bicycle Maintenance and Repair and Park Tool's Big Blue Book), a sawhorse with a clamped-on truing stand and a CD player - all lit by a single, naked 60-watt bulb.

That was three months ago. Along the way, I have uncovered the basic truths of wrenching. Success for every would-be mechanic depends on understanding these vital principles, taught only by immersing yourself, making hideous mistakes and digging yourself out of them, and weaving these lessons into your life as a cyclist and a human being. At least, that's what I'm telling my wife.

Lesson 1: Disassembly Is Too Easy

The Shop is a flurry of activity. After cleaning the drivetrain, always the prudent first step, I dig into the toolbox for the chain tool. I press a pin almost all the way out, wiggle the chain apart, and pull it free. Then, I take off the wheels.

I twist the cable covers out of the shifter pods with a screwdriver, grab a 5mm hex wrench and undo the shift cables from the derailleurs. I pop the housings from the frame, slide them off the cables, and pull the cables out--zzzip! Ah, so satisfying. The 5mm wrench also fits the rear derailleur; it comes off next. Ditto for the stem faceplate...handlebar hangs free...stem slides up, fork drops out--oops, brake still attached...brake lever removed next...

In less than an hour, using little more than a 5mm hex wrench, I have removed most of the parts from my bike. The deconstruction happens so easily that it becomes addictive, and I start removing things (chainring bolts!) just because I can.

It's a trap, I realize, when I pause and find myself standing in the middle of a jumble of dirty parts. I flash to a vision of my future self, pawing like a rabid dog through the mess in search of a missing stem-binder bolt. So I sort through everything while the knowledge of where all the pieces go is still fresh, and place them on the table in order. And I slow down. If my zeal starts to get the better of me again, I say to myself, I will simply remove one component at a time, clean it, inspect it and reinstall it before moving on.

Lesson 2: Organization Saves Time (And Sanity)

My new method, it seems, is working for keeping track of parts but not for tools. I can't find my bottom bracket tool. I used it to remove my BB on one of my last basement forays. So much of the ride depends on the fluid feel of a healthy BB that it's worth getting everything just right, and until now, no problem: After removal, I scrubbed the threads on the frame and cartridge until they were spotless, and smeared a thin layer of grease on them - too much can clog up the installation. With the right amount of grease, I can thread the cartridge and adapter more than halfway in using only my fingers. I just need the BB tool, and my torque wrench, to finish the install.

I dig through the toolbox. There's a BB tool, but it's not the one I need, and I let out a string of creative expletives directed at every component manufacturer I can name for making different types of BBs that require different tools. Above ground, Jen hears me. She opens the basement door, "What are you doing?" Then she draws the line; if I wake up the kids, my Shop session is over.

Mumbling, I dump the contents of the toolbox onto the table. Nope. Under the table? Nothing. I look on the nearby shelves (where I find my 5mm hex; it goes back into the toolbox), around the workstand, behind the CD player, among the kids' summer toys and through boxes of ancient paperwork.

I find it, finally, in a box of old computer cables. My time for the night is up, so I leave the basement defeated, and with my BB only half installed. I spend the next session cleaning up from my search, and I add a key component to The Shop: a freshly emptied cardboard diaper box. From now on tools go back into the toolbox or, if I'm midfix, into the cardboard box.

Lesson 3: Limits Keep You Happy

Here I am, spinning my tire-free rear wheel, which is clamped into my truing stand. The calipers on the stand move closer and closer to the rim until one arm scrapes the sidewall. It's a long scrape, punctuated by one short silence each revolution; not great, but not terrible. I move the calipers so they almost touch the bottom edge of the rim to see if the wheel is round. I spin it again, and the wheel's a little off. This weekend, I'll take it to the shop.

That's right, I'll have my local bike shop fix it. With patience, I've trued wheels before, but this time I just don't want to. I had made the decision before I even set the wheel in the stand.

For the home mechanic, maintenance comes down to desire. When I don't really want to do a project, I take shortcuts and make mistakes, so now I take it only as far as I want. For some people, that means tackling something they've never tried, while for others it means only squirting the chain with lube and using a shop for the rest. Whatever it is, draw that line before you start.

Lesson 4: Small Changes Are Big

My biggest goofs always happen when I'm giddy about installing a new part. I once cut a new fork's steerer tube too short, leaving no room for spacers. Then there was the time I didn't completely tighten the One-Key release caps on my XTR cranks, which ripped the threads off the caps when I tried to remove the cranks. Both cases were a matter of millimeters. I still can't control my excitement about new parts, but now I move in baby steps to ensure that I execute jobs precisely.

So far this time, all is well. The bottom bracket, finally installed, is flawless. I reattach the rear wheel to check the rear derailleur's alignment with the cassette. It lines up perfectly with the smallest cog; I push it by hand into the wheel, and the inner stop holds it in line with the largest cog. I tighten the barrel adjusters, and spin them out a half turn before sliding the new cable into place, with a drop of light grease at each end. The housing glides through. I pull the cable finger tight into the derailleur, and lock it into place. The chain goes back on. I turn the pedals. The bike whirs into action. The shifting smooths out with a few turns of the barrel adjuster. The fine tweaks are enough.

I make one adjustment - one shifter at a time, for example - per night so I feel a sense of accomplishment but not rushed or sick of the project. One fix, and then I leave. Each night, I look forward to the next session. My bike is coming back to life.

Lesson 5: You Never Know It All

Years ago, I watched an old-time master mechanic put hydraulic rim brakes on my bike. He read the manufacturer's instructions, roughly translated into English from a very non-English language. Once through, he put the booklet down and said, "Eh, we'll figure it out." You use what you know to make your way through what you don't know, which is what I'm doing tonight. It seems that the front-end clunk that I thought was coming from my headset isn't. There was no sign of wear; once repacked with grease, the whole assembly was like new. Now I have the bike out of the stand, front brake locked, and I'm rocking the bike back and forth.

Clunk. I wrap my hand around the top headset cup and rock the bike. No movement. Then the bottom, just to be sure. Nothing. I study the fork; it compresses with each push, but the movement doesn't match the clunk.

What else could it be? I keep the front brake locked, put my fingers under the rear of the saddle, and slowly lift. Clunk. Something's loose in the rear of the bike. But I had unbolted the shock early on to check for play in the rear pivots, and they were fine. Then, the lightbulb: If the noise isn't there when the shock is removed, but it is there when the shock is attached, then it must be coming from the shock itself. I lift the bike again, and there's a subtle shift in the rocker arms near the top of the shock.

I read the owner's manual, then call my shop and learn that the problem is a worn bushing/aluminum reducer combo, which is remedied by pressing out the bushing and pressing in a new one. As a bonus, the shop has a heavy-duty version that, I'm told, should last "almost forever." It's a bigger problem than I anticipated, but diagnosing it has me itching to tackle this one myself.

Lesson 6: Passion Is Contagious

My riding friends have discovered my inclination for home wrenching. It's been pretty obvious since the time when I was first learning and said something like "I was adjusting my derailleur last night" just before the derailleur shifted into the rear wheel and was ripped in half. But when my bike is consistently tuned, or when I share insight that others can adopt, I earn a little respect, as well as a reputation for knowing how to fix things in a pinch.

The afternoon after my end-cap painting session, I go to the basement to bring my masterpiece to the surface. My three-year-old son tromps down the steps behind me, and heads to a pile of exiled summer toys.

I take my bike off the stand and pump up the tires. I'm fiddling with a quick-release when I hear the pump working behind me. There's Gabe, pushing on the pump handle, trying to force air into the plastic tires on his Big Wheel.